An STS-125 crew member aboard the Space Shuttle Atlantis captured this still image of the Hubble Space Telescope as the two spacecraft continue their relative separation on May 19, 2009. Credit: NASA.

Backdropped by the blackness of space and the thin line of Earth's atmosphere, space shuttle Atlantis' payload bay, Canadian-built remote manipulator system robotic arm, vertical stabilizer and orbital maneuvering system pods are featured in this image photographed by the STS-125 crew on flight day 10. Credit: NASA.

As Atlantis’ crew prepares for landing Friday, mission managers are closely monitoring a low pressure system that has brought 16 inches of rain in three days to the Shuttle Landing Facility at Kennedy Space Center in Florida.

Forecasters report the system is slowly moving away but it could still bring more rain, possible thunderstorms and winds that could violate the shuttle’s flight rules into the Florida spaceport area. The two Friday landing opportunities are at 10:00 and 11:39 a.m. EDT.

Should mission managers wave off landing the next four opportunities will be Saturday with two at Kennedy and two at Edwards Air Force Base in California. The shuttle has enough supplies to remain in space until Monday.

The next landing opportunity at Florida's Kennedy Space Center will be at 10:11 a.m. ET Sunday.

The STS-125 crew aboard space shuttle Atlantis captured this still image of the Hubble Space Telescope as the two spacecraft begin their relative separation on May 19, 2009, after having been linked together for nearly a week. During the week, five spacewalks were performed to complete the final servicing mission to the telescope. Credit: NASA.

Atlantis and the crew of the STS-125 mission landed safely in California at Edwards Air Force Base after completing the Hubble Servicing Mission on Sunday, May 24, 2009. The almost 5.3-million-mile mission included five spacewalks to repair and upgrade the world-famous observatory. Credit: NASA/Carla Thomas.

When the seven crew members of space shuttle Endeavour meet up with the six astronauts on the international space station in a few days, the 13 visitors from Earth will comprise the largest space get-together.

Endeavour is set to blast off Saturday at 7:17 a.m. ET for a 16-day mission to help expand the space station. The rendezvous will be truly international: Among the 13 crew members of the station and shuttle are Canadian, European and Japanese astronauts, along with Russian cosmonauts

The Japanese Kaguya probe, a robot craft currently orbiting the Moon, has some sensors not found on previous space-faring robots, HD video cameras. The amazing video returned is so clear it's easy to mistake for a computer simulation. Kaguya will be ending its Moon mission at 18:30 UTC on June 10 with an impact on the lunar surface.

Say this for the U.S. space program: we may have spent the last 40 years mostly ignoring the moon, but when we go back, we go back with a bang. Later today — if weather conditions and hardware permit — NASA will launch its much-anticipated and deeply imaginative Lunar Reconnaissance Orbiter (LRO), the first American spacecraft of any kind to make a lunar trip since 1999. Not only will LRO help us study the moon in greater detail than ever before, it should also give us our first look at the six Apollo landing sites since we abandoned the historic campgrounds two generations ago.

Easily the most exciting piece of hardware aboard the ship, however — for lay lunarphiles at least — will be the camera. Even the best reconnaissance photography before the Apollo visits missed things, which is why Apollo 11's landing almost came to grief when Neil Armstrong and Buzz Aldrin found themselves piloting their lander over an unexpected boulder field just seconds before touchdown. That's less likely to happen this time, thanks to a camera that can visualize objects as small as a few feet across. What's more, since the LRO will be in a polar orbit instead of an equatorial one — or, vertical rather than horizontal — the moon's 28-day rotation will eventually carry virtually every spot on the surface beneath the camera's lens.

"The moon will essentially walk around underneath the orbiter," says Garvin. "With the detail we get in the photographs, every picture will be like a mini-landing." That includes photos of the Apollo sites, all half dozen of which should have their portraits snapped. If NASA gets lucky, Garvin believes the first such images could be in hand by the 40th anniversary of Apollo 11, on July 20.